Is strongyloidiasis currently autochthonous in Croatia? A retrospective study

Background: Autochthonous human infections with Strongyloides stercoralis have been well documented in many European regions. By exploring patients' data, we aimed to find elements for its current endemicity in Croatia. Methods: This retrospective descriptive study analysed epidemiological and clinical data of patients treated for strongyloidiasis from January 2010 to May 2019 at a teaching hospital in Zagreb, Croatia. The diagnosis was made by direct methods using Eight microscopy and/or serology. Results: Among 65 patients with strongyloidiasis, 60% were men, and 78.5% were 50-79 y of age. The sensitivity of the examination of three stool samples after concentration, saline provocation and serology was 26.2, 80.7 and 86.2%, respectively. Clinical presentation included asymptomatic patients with eosinophilia (41.5%), chronic symptomatic infection (33.8%), acute infection (18.5%) and hyperinfection (6.2%). Twenty patients (30.8%) were immunosuppressed; among four of whom developed hyperinfection, two died. Initially 71.7% of patients were treated with albendazole and 13.3% with ivermectin, with an equal parasitological cure rate (72.2% and 75%; p=0.09). In 11 patients, acute infection was autochthonous in its origin. Conclusions: Strongyloidiasis is currently endemic in Croatia and immunosuppressed travellers to this region should be advised to take precautions. Patients undergoing immunosuppression and organ donors from Croatia should be screened.